Basically it’s because MS Excel can’t decide how to open the file with such content.
When you put ID as the first character in a Spreadsheet type file, it matches the specification of a SYLK file and MS Excel (and potentially other Spreadsheet Apps) try to open it as a SYLK file. But at the same time, it does not meet the complete specification of a SYLK file since rest of the values in the file are comma separated. Hence, the error is shown.
To solve the issue, change "ID" to "id" and it should work as expected.
This is weird. But, yeah!
Also trying to minimize file access by using file object less.
I tested and the code below works perfect.
import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
public class CsvWriter {
public static void main(String[] args) {
try (PrintWriter writer = new PrintWriter("test.csv")) {
StringBuilder sb = new StringBuilder();
sb.append("id");
sb.append(',');
sb.append("Name");
sb.append('\n');
sb.append("1");
sb.append(',');
sb.append("Prashant Ghimire");
sb.append('\n');
writer.write(sb.toString());
System.out.println("done!");
} catch (FileNotFoundException e) {
System.out.println(e.getMessage());
}
}
}